Mumbai: Sanjeev Khanna, former husband of prime accused Indrani Mukerjea, was today remanded in police custody after being charged with murder in the sensational Sheena Bora case and taken to an undisclosed location for joint interrogation with her and her driver.

Brought here from Kolkota last night, Khanna was produced in Bandra court and remanded to police custody till August 31 after being charged under Sections 364 (kidnapping), 302 (murder), 201 (causing disappearance of evidence) and 120-B (conspiracy) of the IPC.

In what could be crucial in taking the probe forward, police collected a few pieces of bones from J J Hospital, where it was sent in May 2012, a month after Sheena's body was burnt and dumped there.

"The hospital sent its report in 2013 saying it can not determine the age, sex or cause of death on the basis of the bones sent by the Pen police," Hospital Dean Dr T P Lahane said.

"Today, Khar police came to the hospital and collected the bones from us", Lahane said declining to make any comment when asked whether the samples could be vital forensic evidence in the case.

Sheena's brother Mikhail, who had stated that the victim was Indrani's daugher and not her sister, also landed here from Guwahati and promised to cooperate fully with the police in the ongoing probe.

"I will extend full cooperation to Mumbai police. I will get justice for her," Mikhail said.

Mumbai Police Commissioner Rakesh Maria had said last night that presence of the "third accused " (Khanna) would be crucial in unravelling the mystery.

Khanna, in an off-white shirt and khaki trousers, was produced in the court amid tight security with his face covered with a white cloth.

The police alleged in the court that Khanna had played an active role in the conspiracy and murder of 24-year-old Sheena and he had to be taken to the spot where she was killed on April 24, 2012.